Mezzotint rocker

ABSTRACT

This invention consists of a mezzotint rocker which is used in fine art etching and engraving for rendering black or gray areas. It differs from the existing old style rocker in that its cutting teeth are cut on a beveled surface which is at an angle to the face of the rocker, rather than on a surface which is at rightangles to the face of the rocker as is the case in rockers used prior to this invention.

United States Patent [191 Noestheden MEZZOTINT ROCKER [76] Inventor: Andy B. Noestheden, 817 Chatham St. East, Windsor, Ontario, Canada 22 Filed: Apr. 28, 1972 21 Appl. No.: 248,458

[52] US. Cl 8l/9.2, 30/355, 30/358 [51] Int. Cl B4lb 1/06 [58] Field of Search..... 81/9.2, 9.21; 30/l64.9, 169,

[56] References Cited UNITEDSTATES PATENTS 202,444 4/1878 Legouge 30/169 [451 Fens, 1974 Primary ExaminerJames L. Jones, Jr. Assistant Examiner-James G. Smith [5 7] ABSTRACT This invention consists of a mezzotint rocker which is used in fine art etching and engraving for rendering black or gray areas. It differs from the existing old style rocker in that its cutting teeth are cut on a beveled surface which is at an angle to the face of the rocker, rather than on a surface which is at rightangles to the face of the rocker as is the case in rockers used prior to this invention.

4 Claims, 6 Drawing Figures Pat ented Feb. 5, 1974 lnvenior m y D m E m m M S E W 5 Y 0% NW A FIG-4 F165 MEZZOTINT ROCKER This invention relates to a tool known as a rocker. It was originally used primarily as a tool in the production of'the art formknown as mezzotint.

The fine art known as etching and engraving consists of cutting a drawing on the surface ofa metal plate either by means of an acid or a sharp tool. The plate is covered with a form of printers ink and the drawing is transferred to paper by passing the plate and paper through rollers under pressure.

One branch of engraving is known as mezzotint. This consisted of raising a burr all over the plate so that normally it would print a very blacksurface on the paper. By scraping away the burr in various areas of the plate and varying the amount of scraping, various degrees of blacks and grays can be obtained in the printing process, thus reproducing the intended drawing.

The tool used in the production of the mezzotint is known as a rocker and it consists mainly ofa handle to which is attached a steel plate, the outer edge of which is in the form of the arc of a circle. This edge is cut by a series of closely spaced, fine, parallel lines so that they terminate at the curved edge in very sharp points. By continuous rocking of this tool on the metal plate, the surface of the plate is roughened to give a black print on the paper.

The art of making mezzotints is not being practiced to any great extent at the present time because of the difficulties involved in producing the required artistic results and because of the consumption of a great deal of time required. However, the rocker is still very popular as a subsidiary tool in etching and engraving, by means of which very dark or black areas can be produced easily and effectively.

The rocker used at the present time has seen very little change in the last 100 years. It is therefore the object of this invention to provide a rocker which is considerably more adaptable to modern methods and requirements.

This is accomplished in the invention in the following manner:

a. Unlike the old design, in this invention the sharp teeth on the ,curved edge of the rocker meet the metal at 90 at all times. This provides a better burr, under greater control,.with less strain and effort on the part of the artist. It also lessens the chance of teeth breaking off during operation.

b. Thedesign of the invention also lends itself to easy sharpening by applying the sharpening oil stone to the edge of the face.

c. The rocker in the invention is also designed for perfect balance and fit in the hand of the user.

In describing the invention reference will be made to the-attached drawings in which: 7

FIG. 1 is a side view of the invention,

FIG. 2 is a front view of the invention,

FIG. 3 is a rear view of the invention,

FIG. 4 shows a variation in the design of the invention,

FIG. 5 is another variation in the design of the invention, and

FIG. 6 shows an enlarged view of the teeth.

In the drawings is shown a rocker consisting of a flat plate I of an oil hardened high quality steel in the shape of a truncated segment of a circular plate. The round edge of the plate 1 is beveled part way down as shown on face 2 at an angle ranging between 45 and 75 with the vertical, however the preferred angle for that purpose is 60. This bevel terminates at about the center line of the thickness of the plate 1 and then continues at a further angle down towards the opposite face of plate 1 to form a second face 3 at the round edge of the plate 1.

The beveled face 2 is cut with a plurality of closely cut grooves to form a series of equally spaced teeth 4 which terminate at the curved edge in vcry sharp points which are somewhat rounded as shown in the enlarged and exaggerated view in FIG. 6. It has been found experimentally that for average requirements the minimum number of such teeth should be about 80 teeth per inch of arc. A lesser or larger number of teeth can be used where required for special effects.

The plate 1 is provided with a centrally located stem 5 which extends from its base by means of which the said plate is attached to a handle 7 preferably made of wood. The top of the handle 7 is reinforced with a metal band 6. In the drawings the plate 1 is shown attached to the handle by means of a forced fit. However, the stem 5 can be made threaded so that it can be screwed into the handle.

In FIGS. 4 and 5 two variations are shown in the construction of the rocker. In FIG. 5, the following items correspond with each other 12 and 1, l3 and 2, 14 and 4, 15 and '3. Actually in this variation, the stem 5 is eliminated, and a centrally located bolt hole is provided at the bottom of the plate 12. A handle 17 is provided I at its top with a clevis 16, into which fits the plate 12 and in which the said plate is held rigidly by a bolt 18, which passes through the said plate and clevis.

In FIG. 4 the steel plate 8 has anupper round edge which is flat and at right angles to the face of the plate. Its lower edge consists of a straight flat surface beveled at an angle to the face of the plate. The upper round edge is cut into a plurality of teeth 9 which are similar to the teeth 4 of FIG. 1. This plate is attached to a specially designed handle 10 to which the plate 8 is attached by a bolt 11. The upper part of the handle 10 is shaped to hold the plate 8, when fitted inside of it, at angle which will place the cutting edges of the teeth 9 at the same angle with the work as the teeth 4 on the beveled surface.

Having described the invention, what I claim is:

l. A mezzotint rocker comprising a flat plate of hardened metal in the shape of a truncated segment ofa circular plate; the curved outer rim of said plate having a beveled face extending from one flat face of said plate towards the center of the thickness of said plate to form a sharp outer edge; said beveled face continuing in a further bevel down towards the opposite flat side of said plate; a series of closely spaced parallel or radial teeth cut in the first mentioned bevel face, said teeth terminating in sharp points on the said outer edge; and

I a centrally located hole near the bottom edge of said plate for passing a bolt therethrough by means of-which the said plate can be attached to a handle.

2. A mezzotint rocker comprising a Hate plate of hardened metal in the shape of a truncated segment of a circular plate; the curved outer rim of said plate having a beveled face extending from one flat face of said plate towards the center of the thickness of said plate to form a sharp outer edge; said beveled face continuing in a further bevel down towards the opposite flat side of said plate; a seriesof closely spaced parallel or radial teeth cut in the first mentioned bevel face, said teeth terminating in sharp points on the said outer edge; a centrally located stern extending from the truncated bottom of said plate for attaching a handle 3. A rocker such as described in claim 2 in which the said teeth number between 65 and 120 teeth per linear inch of arc.

4. A rocker such as described in claim 2 in which said thereto; and a handle attached to said plate by means 5 teeth terminate in minutely rounded points.

of which said rocker is operated. 

1. A mezzotint rocker comprising a flat plate of hardened metal in the shape of a truncated segment of a circular plate; the curved outer rim of said plate having a beveled face extending from one flat face of said plate towards the center of the thickness of said plate to form a sharp outer edge; said beveled face continuing in a further bevel down towards the opposite flat side of said plate; a series of closely spaced parallel or radial teeth cut in the first mentioned bevel face, said teeth terminating in sharp points on the said outer edge; and a centrally located hole near the bottom edge of said plate for passing a bolt therethrough by means of which the said plate can be attached to a handle.
 2. A mezzotint rocker comprising a flate plate of hardened metal in the shape of a truncated segment of a circular plate; the curved outer rim of said plate having a beveled face extending from one flat face of said plate towards the center of the thickness of said plate to form a sharp outer edge; said beveled face continuing in a further bevel down towards the opposite flat side of said plate; a series of closely spaced parallel or radial teeth cut in the first mentioned bevel face, said teeth terminating in sharp points on the said outer edge; a centrally located stem extending from the truncated bottom of said plate for attaching a handle thereto; and a handle attached to said plate by means of which said rocker is operated.
 3. A rocker such as described in claim 2 in which the said teeth nuMber between 65 and 120 teeth per linear inch of arc.
 4. A rocker such as described in claim 2 in which said teeth terminate in minutely rounded points. 